Specifications

- Generally, trade-in vehicles must get 18 or fewer miles per gallon (some very large pickups and cargo vans have different requirements.)

- Trade-in vehicles must be registered and insured continuously for the full year before the trade-in.

- You don't need a voucher; dealers will apply a credit at purchase.

- Program runs through Nov. 1 or when the funds are exhausted, whichever comes first.

- The program requires the scrapping of your eligible trade-in vehicle and that the dealer disclose to you an estimate of the scrap value of your trade-in. The scrap value, however minimal, will be in addition to the rebate, and not in place of the rebate.

Congress approved the program in June, and President Barack Obama signed it June 24. Dealerships have been awaiting the official rules, however. Those came out Friday.

Under the deal, some car owners can get $3,500 to $4,500 off the sticker price when they trade for a more efficient new ride. Their current car must be less than 25 years old, and most must get less than 18 miles per gallon of gas.

Owners at Steamboat Motors and Cook Chevrolet, Jeep and Subaru said they'd heard from customers interested in the program.

Steamboat Motors owner Jeff Steinke said he'd received only a few calls as of early Friday afternoon.

"Typically, whenever anybody rolls out any kind of program, it's a few weeks when the program is in the marketplace before you see people coming in," he said.

As people get details, interest probably will pick up, Steinke said.

"Obviously, we're going to be out there with everybody," he said. "There's going to be so much information thrown out there over the next several months."

Congress put $1 billion into the program. The Car Allowance Rebate System will run until Nov. 1 or until funds run dry, whichever comes first. The program is simple, Steinke said. People can enter the vehicle identification number of their car and the VIN of the one they'd like to buy and find out whether they qualify.

Dealers give the discount and get reimbursed.

Car sellers won't accept rundown rust buckets, however. All cars traded in must be running, and an owner must have owned them for a continuous year. Cook Chevrolet owner Scott Cook said people had been holding off, waiting to see whether their cars qualify for the trade-in deal.

The dealers can't resell the cars. Doing so would defeat part of the purpose of the program, which is to get fuel-inefficient cars off the road.

"This is a car stimulus, sure, but it's also green," Cook said. "They're trying to get people out of cars that pollute more and use more gas to cars that pollute less and use less gas."

Steinke said he had seen limited interest in the program. He did have a customer in Friday morning who probably would be able to trade an older Jeep for a new Jeep Liberty under the program.

Because of stricter Environmental Protection Agency mileage standards, most new cars are more fuel-efficient than older counterparts, he said. Steinke said he was seeing increased demand at the dealership, anyway.

He expected interested in the Car Allowance Rebate System to pick up.

"Funny thing is, we as taxpayers may as well use it because we're paying for it anyway," Steinke said.